The US-backed military ruler fuelled Islamist anger with this week's army assault on the pro-Taliban mosque complex in Islamabad that left 86 dead in a fierce 36-hour battle, most of them militants.

In the capital, hundreds called for holy war and chanted "Musharraf is a killer" and "Glory be to the Red Mosque martyrs" at a rally organized by Pakistan's main alliance of radical parties, the Mutahida Majlis-e-Amal.

"This carnage will prove to be the last nail in the coffin of Musharraf's dictatorial rule in Pakistan," the group's deputy leader Maulana Abdul Ghafoor Hydri told the gathering.

"Now there will be Red Mosques everywhere in Pakistan."

The protest was one of scores across the world's second largest Islamic nation, which were called on the traditional Muslim day of prayer to condemn the military raid that turned Islamabad into a war zone this week.

The attack on the mosque and its all-female Islamic school ended a months-long standoff in which hardline vigilantes raided video shops and beauty parlours and abducted six Chinese women they accused of being prostitutes.

Pakistan, on high alert for revenge attacks, boosted security Friday, deploying tens of thousands of police and troops, after al-Qaeda urged Pakistanis to rise up against the US-backed government.

Two suicide blasts killed eight people on Thursday, and police on Friday said they seized three men and a car packed with seven suicide vests, 100 mortar shells and other explosives in northwestern Dera Ismail Khan town.

In the Islamist heartland city of Peshawar, near the Afghan border, some 2,000 people shook their fists and chanted "Destroy Musharraf" when a top cleric asked them to follow the lead of rebel leader Abdul Rashid Ghazi.

Ghazi died in a hail of bullets in the Red Mosque Tuesday.

In Lahore, 20,000 men, women and children Friday also offered prayers for the victims of the army raid in a meeting at a mosque run by a hardline Islamist group blacklisted by the United States as a terrorist organisation.